Dragon SpX-3 - Mission Profile

Additional Resources

Current Dates

Launch: April 18, 2014 - 19:25 UTC

Capture: April 20, 2014 - 11:14 UTC

Departure & Landing: May 2014

Ascent & Flight Day 1: Early Orbit Operations

Dragon SpX-3 is the first Dragon flight to use the upgraded Falcon 9 v1.1 (F9R) Rocket that made its first launch in 2013. With its increased performance, the Falcon 9 can lift a fully loaded Dragon spacecraft to carry more cargo to the Space Station. Additional performance of the Falcon 9 v1.1 will be used to attempt to return the first stage for a Soft Splashdown in the ocean. It is also the first F9R rocket to fly, featuring four deployable landing legs on its first stage.

Overall, the two-stage Falcon 9 v1.1 stands 68.4 meters tall, is 3.66 meters in diameter with a liftoff mass of 505,000 Kilograms. The launcher can deliver payloads of up to 13,150 Kilograms to Low Earth Orbit and 4,850kg to Geostationary Transfer Orbit.

Launch Day for the SpX-3 mission begins with Vehicle Power Up and Countdown Operations that include the final rounds of testing of the Falcon 9 Rocket and the Dragon Spacecraft. Also, the launch vehicle goes through the fueling process and Dragon is configured for Operations in Orbit. As part of propellant loading, the first stage of the rocket is filled with approximately 382,000 Kilograms and the second stage is filled with around 70,800 Kilograms of Liquid Oxygen and Rocket Propellant 1. A detailed Countdown Timeline is available here.As the countdown enters its final hour, the launch team will start final reconfigurations for the Terminal Countdown Sequence. At L-13 minutes, the launch team will be polled for a GO/No GO to press into the final countdown sequence.

The Terminal Countdown Sequence gets underway at T-10 minutes and features the final set of reconfigurations to transition the Falcon 9 to its launch configuration. The flight control system will be enabled and the nine Merlin 1D engines on the first stage will start their Chilldown Sequence at T-9:43 to start conditioning the engines for blastoff as pre- and bleeder-valves are opened. By T-7 minutes, the Dragon spacecraft will have switched to internal power and transition to their flight configuration. At T-6 minutes, the automated countdown sequencer is being started up.

At T-4 minutes and 30 seconds, the Falcon 9 launch vehicle is transitioned to internal power. 20 seconds later, the Launch Vehicle Release System begins its own countdown auto sequence. At T-3:40, the TEA-TEB Ignition System of the first stage is activated followed by transferring the Flight Termination System to internal power and its transition to auto mode. At T-3:02, Liquid Oxygen Topping is terminated followed by a Thrust Vector Control System test on the second stage. At T-2 minutes 30 seconds, the launch team completes a final status check and the Range is verified clear for launch at T-2 minutes

Helium Loading is terminated at T-95 seconds, final engine chilldown starts at T-90 seconds and the purge of the nine Merlin 1D engines starts at T-80 seconds. One minute before liftoff, the Flight Computer starts-up and assumes control over all the vehicle's functions.

The nine Merlin Engines on the first stage complete a Thrust Vector Control System test at T-50 seconds and all propellant tanks begin their pressurization to flight level at T-40 seconds. As part of the final steps before ignition, the tanks reach flight pressure and the pyrotechnics of the vehicle are armed for flight.

Three seconds ahead of launch, the nine Merlin 1D engines are ignited and soar up to full thrust. Each of the nine Merlin 1D engine provides 654 Kilonewtons of thrust for a collective liftoff thrust of 600,200 Kilograms. Computers will monitor engine start-up and verify that all nine engines reach operational conditions before the vehicle is committed to launch.

When clocks reach zero, the 68.4-meter Falcon 9 will blast off and slowly clear its tower as it has a relatively low initial thrust-to-weight ratio of 1.25. After the vehicle clears the tower, it makes a short vertical ascent before beginning its pitch&roll. On its way uphill, Falcon 9 burns nearly 2.2 metric tons of propellants per second. Falcon 9 passes Mach 1 a little more than one minute into the flight and passes Maximum Dynamic Pressure about one minute and 23 seconds after liftoff.

Photo: SpaceX

Time

Event

T-0:00:03

Merlin Engine
Ignition

T~0:00:15

Start Pitch
Maneuver

T+0:01:10

Mach 1

T+0:01:23

Maximum Dynamic
Pressure

T~0:01:30

Stage 2 - Merlin
Vac Engine Chilldown

T~0:02:10

Merlin Throttle
Down

T+0:02:41

MECO - First
Stage Cutoff

T+0:02:44

Stage Separation

T+0:02:45

Second Stage
Ignition

T+0:03:25

Dragon Nose Cone
Jettison

T+0:08:55

Terminal
Guidance Mode

T+0:09:05

Flight
Termination System Safing

T+0:09:40

Second Stage
Cutoff

T+0:10:15

Spacecraft
Separation

T+~0:11:00

Dragon Solar
Array Deployment Sequence

Photo: NASA/SpaceX

After passing the two-minute mark into the flight, the rocket will enter its throttle segment - slowly throttling down its first stage engines to limit acceleration as the rocket approach shutdown. >>>Ascent Data Page

First Stage Cutoff occurs 2 minutes and 41 seconds into the flight. The two stages of the Falcon 9 separate three seconds after MECO as the pneumatic separation system is initiated and the first stage is pushed away. One second after staging, the Merlin 1D Vac engine of the second stage is ignited, soaring up to full thrust of 81,700 Kilograms for a burn of about seven minutes to reach Low Earth Parking Orbit.

During the second stage burn, the Dragon Nose Cone separates to increase ascent performance - exposing the Common Berthing Mechanism. The Nose Cone is used to protect the docking system and instruments of Dragon while the vehicle is waiting for launch under Florida Skies and during the initial ascent portion while the vehicle is flying through the dense atmosphere.

Spending the final 45 seconds of its burn in Terminal Guidance Mode, the second stage shuts down at T+9:40 when the vehicle has reached its planned insertion orbit at an altitude of 325 Kilometers and an inclination of 51.6 degrees. Half a minute after engine shutdown, the Dragon Spacecraft is released. To complete Orbital Insertion, Dragon will separate the solar array fairings and deploy its two solar arrays. Teams at SpaceX Mission Control in Hawthorne, California, will conduct a vehicle status checks to verify Dragon is in good condition and ready for on-orbit operations.

Dragon Mission Control and ISS Flight Controllers in Houston, Texas, will be working closely together throughout the mission.The
first day in space is dedicated to Far Field Phasing Maneuvers and
vehicle checkouts to make sure Dragon was not harmed during ascent. Just before passing the T+2.5-hour mark, at T+2:26, Dragon will start
deploying the GNC Bay Door to put required Rendezvous instruments in
place. DragonEye, the Vehicle's Rendezvous and Navigation Instrument Suite,
includes a LIDAR (Light Detection And Ranging) Imager and a thermal Instrument. Just after being deployed, both of
these instruments will be activated and undergo thorough checkouts. Also located on the GNC Bay Door is the SSRMS Grapple Fixture needed for Capture and Berthing, so a good lock of the door is required for mission success. Dragon also starts orbit adjustment maneuvers on Flight Day 1 with the first burn being a circularization maneuver to increase the low perigee of the injection orbit.

Dragon Communications System

Image: SpaceX

Dragon Spacecraft Illustration

Image: SpaceX

Returning the First Stage

Photo: SpaceX/Elon Musk

Photo: SpaceX

Cassiope First Stage Touchdown

Following liftoff, the stage will burn its nine Merlin 1D engines for a little more than 2.5 minutes to deliver the second stage to its planned trajectory from where it can deliver Dragon to the desired Low Earth Orbit to begin its rendezvous with ISS.

Shortly after separation, the first stage uses its cold gas attitude control system to re-orient to an engine-forward flight. Before re-entering the atmosphere, three of the Merlin 1D engine ignite briefly to slow the rocket stage down so it can withstand the re-entry environment. During entry, the stage will be kept stable by its very low center of gravity. Once in atmospheric flight, the four legs will be deployed using a high-pressure Helium system.

When deployed, the legs have a span of about 18 meters. The legs consist of a carbon fiber and aluminum honeycomb structure with a mass of about 2,000 Kilograms. Fully deployed, the legs will provide additional aerodynamic stability. The first Falcon 9 splashdown attemptlast September experienced an uncontrollable roll during its final moments that caused the landing burn of the center engine to be cut short because the propellant was being centrifuged up the tank walls, damaging the tank baffles & leading to debris entering the engines.

With the legs, it is hoped that this roll will not occur again so that the center engine can be fired just before landing in the Ocean at a gentle speed. A recovery attempt of the stage will likely be made, but SpaceX is not counting on the the first stage making it back in one piece.

The first return attempts of the Falcon 9 first stages are considered experimental and are not expected to succeed every time as SpaceX fine tunes its systems and sequences, entering unknown territory on the path to making the Falcon 9 re-usable.

These soft splashdown attempts will continue until the full landing regime can be tested with the Grasshopper vehicle.

Flight Day 2: Additional Checkouts & Orbit Adjustments

On Flight Day 2, the Dragon Spacecraft will make several Engine Burns, called Height Adjustment and Coelliptic Burns, to adjust its Orbit to set the Stage for a Rendezvous with the Space Station on Flight Day 3. These Burns are known as Far Field Phasing or Height Adjust Burns and will increase Dragon's Orbital Altitude and make its orbit circular.

Flight Day 3: Rendezvous and Capture

On Flight Day 3, the Dragon Spacecraft will make several Engine Burns, called Height Adjustment and Coelliptic Burns, to adjust its Orbit to set the Stage for a Rendezvous with the Space Station. These Burns are known as Far Field Phasing or Height Adjust Burns and will increase Dragon's Orbital Altitude.As Dragon gets closer to the International Space Station, Rendezvous Operations will get underway. The spacecraft will enter the 28-Kilometer Communications Zone around ISS and a direct UHF link between ISS and Dragon will be established over the course of the approach. The Spacecraft will use a proximity communications link for Relative GPS Communication with ISS and the Commercial Orbital Transportation Services (COTS) Ultra High Frequency (UHF) Communication Unit (CUCU) aboard the Station will also be used to communicate with the Spacecraft. The Commercial Communications Infrastructure aboard ISS was set up while the Space Shuttle was still flying - bringing components including the CUCU to the Station in 2009.

Photo: NASA

Testing of the System was underway in 2010 and was used for Proximity Operations for the first time in 2012 for Dragon C2+. Using Absolute GPS, Dragon will make a Height Adjust & Coelliptic Burn Pair to reach a position 2.5 Kilometers below and behind the station. By that time, Integrated Operations between SpaceX and NASA Mission Control Centers will be underway with Visiting Vehicle Officers and other Flight Controllers making direct communications in order to stay up to date on Vehicle and Rendezvous statuses.

Image: NASA

At 2.5 Kilometers, the Control Teams are polled for the next HA/CE Burn before Dragon is allowed to fire its engines again taking it closer to ISS. At that point, Dragon switches to the Relative GPS Navigation System for Proximity Operations. While getting closer to the Station, Dragon can perform several Mid-Course Correction Burns to adjust its trajectory to the Station's R-Bar. Approach Initiation occurs at 1.4 Kilometers to ISS. Aboard the Space Station, the Crew begins monitoring Dragon at a Distance of 1000 meters ready to take action if necessary.

Koichi Wakata and Rick Mastracchio will be in charge of Dragon Operations, being stationed in the ISS Cupola where they can monitor Dragon and send commands via the CUCU. The next Height Adjust Burn is performed to take Dragon right on the R-Bar that is an imaginary line connecting ISS and the center of Earth. The vehicle is expected to acquire the R-Bar at a distance of 350 meters to the Station. Dragon performs a 180-degree Yaw-maneuver to point its nose to the correction orientation for final approach and possible Contingency Maneuvers.

After approaching 100 more meters, Dragon will automatically enter a period of Stationkeeping. At the 250-Meter Hold, Dragon will complete final adjustments and verifications of the LIDAR and Thermal Imager Proximity Navigation Instruments. NASA and SpaceX Mission Controllers will be polled before the approach resumes. After Mission Control has verified that Dragon is receiving correct navigation data and is in good shape, the Approach will be re-started and Dragon will make short engine pulses to re-initiate the Rendezvous.

At a distance of 200 meters, Dragon enters the ISS Keep Out Sphere where the highest safety standards have to be met by Visiting Vehicles. The ISS crew has different commands they can send to Dragon: A HOLD Command will pause the Rendezvous with Dragon reducing its relative velocity to zero to give teams time to assess a possible problem, a RETREAT command has Dragon going back to either the 250-meter or 30-meter hold point, depending on its distance to ISS and in the event of a larger problem, the crew can send the ABORT Command that initiates a larger burn of Dragon's Draco thrusters to bring Dragon away from ISS rather quickly.

SpaceX can also issue these commands from their Control Center should flight controllers or computers detect an off-nominal situation. All these commands and their initiation from ISS and the ground were demonstrated on Dragon's first ISS Mission back in May 2012 when the vehicle went through extensive demonstrations before being captured.

Image: SpaceX

Arriving at 30 meters, Dragon will hold once again to give mission controllers time for another assessment of its systems before performing the GO/No GO Poll for final approach. Initiating the final approach, Dragon will move to ISS at a very gentle speed and stop its approach at 10 meters - known as the Capture Point. When it is verified that Dragon is in the proper position, Free Drift will be initiated disabling all of Dragon's Thrusters. The Space Station Robotic Arm will then be used under the control of Koichi Wakata and Rick Mastracchio to capture the spacecraft.

SSRMS will
capture Dragon and start a delicate maneuver to place the vehicle
above its desired berthing position at the Earth-facing (nadir) Common
Berthing Mechanism on the Harmony Module. Once in the pre-berthing position, the Crew will perform a visual inspection of the spacecraft's Common Berthing Mechanism and associated O-Rings to make sure no damage or debris is in the area that needs to form a tight seal in order to hold pressure. Also in that position, Dragon rotates its Solar Arrays to the proper configuration for docked operations before the Robotic Arm will resume motion to position Dragon for Berthing. Four Ready to Latch Indicators
will be used to verify that the Spacecraft is in the correct position
and ready for berthing. Procedures will begin to perform first stage
capture of the Vehicle and allow the SSRMS to go limp. To structurally attach Dragon to ISS, four sets of four Bolts are driven in a choreographed manner to install the spacecraft.

Afterwards, second stage capture will be performed and Dragon will be secured in place forming a hard-mate between Station and the Spacecraft marking the official start of docked operations. The Robotic Arm will return to its pre-grapple position to finish the day's work.

Capture and Berthing Animation

Flight Day 4: Leak Checks and Hatch Opening

Photo: NASA

After being berthed the day before, Dragon will already be hard-mated to ISS when the Crew's Day on Flight Day 4 starts. Before starting FD4 Operations, the crew will take care of any open items from Flight Day 3. The vestibule between the hatches of Harmony and Dragon will be pressurized and a series of leak checks will be completed to make sure the seal between ISS and the Spacecraft is tight. Leak checks typically take one hour. When leak checks are complete, Mission Control will give a go for Hatch Opening.

Once the Harmony Hatch is open, the Crew Members will start the Vestibule Outfitting Task which involves the installation of ducts and the removal of equipment that was needed to bolt Dragon in Place. The crew will remove multi-layer insulation from the hatchway and set up their tools for the procedure. Four Control Panel Assemblies will be removed and Dragon will be hooked up to ISS Data and Power Systems via redundant jumpers before Dragon's Hatch is opened.

Once both Hatches are open, the crew will perform Air Sampling as part of initial ingress operations wearing protective gear as they inspect the interior of the Dragon for any damage or Foreign Object Debris.

The team will assess the air inside Dragon before Mission Control gives a GO for Dragon ingress. At that point, the cargo transfer portion of the mission can get underway.

Cargo Operations

During the docked phase of the Mission, the crew aboard the International Space Station will perform many hours of Cargo Operations. Cargo items delivered on Dragon will be offloaded and placed aboard the Space Station. Afterwards, the crew will load cargo on board the Dragon Spacecraft that will return to Earth inside the capsule. On the SpX-3 Flight, Dragon will transport 1,580 kilograms of cargo to ISS and will return ~1,500 kilograms.

Dragon SpX-3 will deliver two external payloads installed inside its Trunk Section - the HDEV, High Definition Earth Viewing Payload, and OPALS, the Optical Payload for Lasercom Science. The two payloads will be removed from Dragon's trunk by the Dextre robot during the docked mission. HDEV and OPALS will be installed robotically - HDEV is planned to reside on the Columbus External Payload Adapter while OPALS is planned to be installed on Express Logistics Carrier 1. Both payloads will be pointing nadir. HDEV will provide HD views of Earth using four different commercially available cameras to evaluate the cameras for use on future space missions with special focus on the durability of the cameras in the radiation environment of Low Earth Orbit. OPALS will demonstrate a Laser Communications System for data transfer from Low Earth Orbit.

Return -1 Day

After cargo operations are complete, the Dragon Spacecraft will be closed out and its hatch will be closed. Afterwards, the vestibule will be outfitted for unberthing. Ducts & Jumpers will be removed and the Control Panel Assemblies needed to drive bolts will be re-installed.

Photo: NASA

Once Harmony's hatch is closed once again, the leak check process will be repeated to make sure that the hatches are closed and latched properly. Once leak checks are complete, the vestibule between the two spacecraft will be depressurized to prepare for the unberthing of Dragon.

Unberthing, Release, Entry and Landing

Photo: NASA

The Space Station Robotic Arm will be used to grapple Dragon before bolts are driven to release the Spacecraft. Once Dragon is free, the Robotic Arm will maneuver it to its Release Position 10 Meters from the Space Station. Dragon and ISS will be in Free Drift Mode at that point with all Thruster Systems being inhibited. At that time, Dragon's Navigation Instruments will undergo checkouts to make sure the vehicle is getting correct navigation data.

Once all checks are complete and both Mission Control Centers have given the GO for release, the Dragon vehicle will be ungrappled and the SSRMS will retreat. Dragon will re-activate its thrusters and recover from Free Drift. Three Engine Burns will be performed by the Vehicle to leave the vicinity of the Space Station.

One minute after release, Dragon makes a very gentle thruster impulse to initiate a slow opening rate between itself and ISS followed two minutes later by another departure burn to depart the immediate vicinity of ISS.

After another 180-degree Yaw Maneuver, Dragon performs its Separation Burn about 10 minutes after release to depart the Space Station and KOS for good. Mission Control Houston will verify that the Vehicle is on a safe path away from ISS.

Image: NASA

While moving away from the Station, Dragon will close its Guidance Navigation and Control Bay Door to protect the instruments inside from the Re-Entry Environment. About six hours after release, Dragon will be at a safe distance to the Station to fire its engines and make the Deorbit Burn taking it on a trajectory to re-enter Earth's Atmosphere. The Deorbit Burn will have a duration of about 9 to 10 minutes slowing the vehicle down just enough to place its on a path to intercept the atmosphere. 20 Minutes after the conclusion of the Deorbit Burn, Dragon hits Entry Interface and starts to feel the effects of the dense portion of Earth's Atmosphere.

During the Re-Entry Process, Dragon's PICA-X Heat Shield has to withstand temperatures of up to 1,600°C. PICA-X is derived from NASA’s phenolic impregnated carbon ablator heat shield, also called PICA. This heat shield has a substantial flight heritage. The PICA-X version is expected to be re-usable many times without showing a high degree of degradation. This design also provides high flexibility in the nature of a mission as it can also support re-entries at velocities exceeding typical speeds of Low Earth Orbit Missions. During the Entry Phase, Dragon uses its Draco Thrusters to stabilize its position and control its lift to precisely target the desired landing location.

About 10 minutes before Splashdown, at an altitude of 13.7 Kilometers, Dragon opens its dual Drogue Chutes slowing the vehicle down. Full deployment of the Drogues triggers the Main Chute Opening Command. This occurs at an altitude of 3 Kilometers. Flying under the Main Chutes, Dragon is slowed to its landing speed of 17 to 20 Kilometers per Hour. The vehicle will make a splashdown landing about 450 Kilometers off the coast of California. The Dragon Spacecraft will be recovered by a Barge that is equipped with a crane to pull it out of the Water.

Image SpaceX

Image: SpaceX

On board will be approximately 12 SpaceX engineers and technicians as well as a 4-person dive team. It will be returned to land shortly after landing.Time-critical Experiments will be returned to NASA within 48 hours.

Photo: NASA

Photo: SpaceX

Overview Timeline

Flight Day

Date

Event

1

Apr 18

Countdown Operations

Powered Ascent

Orbital Insertion

Solar Array Deployment

GNC Bay Door Opening

Spacecraft Checkouts

Far Field Phasing

2

Apr 19

Phasing & Orbit Adjustments

Additional Dragon Checkouts

3

Apr 20

Rendezvous

Approach

R-Bar Acquisition

Final Approach

Capture

Berthing

First&Second Stage Capture

3/4

Apr 20/21

Leak Checks

Vestibule Outfitting

Hatch Opening

Initial Ingress

5-?

Apr 21

Cargo Operations

to ?

External Cargo Ops

?

R-1

Egress

Hatch Closure

Leak Checks

Vestibule Outfitting

?

R-0

Unberthing

Release

Separation Burns

Deorbit Burn

Re-Entry

Landing

Recovery

Updated: April 17, 2014

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